Rotary brush



y 1968 L. G. HOLDER ET AL 3,382,521

ROTARY BRUSH Filed Feb. 27. 1967 INVENTORS L0) GENE HOLDER JOSEPH A.KAS/VY/K MJW M y ATTORNEYS United States Patent 3,382,521 ROTARY BRUSHLoy Gene Holder, Sheffield Lake, and Joseph A. Kasnyik, Parma, Ohio,assignors to The Osborn Manufacturing Company, Cleveland, Chin, acorporation of Ohio Filed Feb. 27, 1967, Ser. No. 618,659 7 Claims. (Cl.15-198) ABSTRACT OF THE DISCLOSURE A power driven rotary cup brushhaving relatively shallow sheet metal inner and outer cup portionsformed to facilitate controlled bodily radially outwardly swingingmovement of the twisted wire bristle knots or tufts for more effectivebrushing action coupled with much increased brush life.

This invention relates as indicated to a rotary brush and moreparticularly to a power driven cup brush having twisted wire knots ortufts.

Power driven cup brushes are well-known in the art and have beenemployed for many years for such purposes as cleaning castings, removingweld spatter, and the like. They are commonly mounted on the ends offlexible shafts driven by power tools which are frequently held by theoperator for off-hand use. Particularly when the tufts are made of heavygauge wire such brushes are difficult to handle and consequently tiringto the operator. Also, in view of the harsh working conditions to whichthey are frequently subjected the working life of such brushes may berelatively short, on the order of five hours, the brushes deterioratingdue to long fracture of the bristle wires long before the bristles areworn down to unusably short lengths from actual wear. A primary objectof the invention is to provide a novel power driven rotary cup brushwhich will have a much increased useful working life, which will be mucheasier for the operator to manage, and which will have improved brushingaction on the work. These and other objects and advantages of thepresent invention will become apparent as the following descriptionproceeds.

To the accomplishment of the foregoing and related ends, the inventionthen comprises the features hereinafter fully described and particularlypointed out in the claims, the following description and the annexeddrawing setting forth in detail certain illustrative embodiments of theinvention, these being indicative however of but a few of the variousways in which the principle of the invention may be employed.

In said annexed drawing:

FIG. 1 is a plan view of a power driven rotary cup brush illustratingthe principle of the invention, a number of the twisted tufts beingomitted better to disclose the internal construction of such brush; and

FIG. 2 is a transverse diametral section taken on the line 2-2 of FIG.1, also indicating in dash line the generally radially outward positionassumed by the tufts under the influence of centrifugal force.

Referring now in more detail to the drawing, wherein like parts areindicated by like reference numerals, such brush comprises a shallowouter sheet metal cup portion 1 having a flat inner disc portion 2 and agenerally radially outwardly turned lip portion 3. Juxtaposed againstthe inner face of such flat cup portion 2 is a much heavier sheet metaldisc 4 the outer peripheral portion of which is dished and provided witha large number of closely spaced circumferentially arranged apertures 5through which the wire bristle tufts 6 are threaded. Such apertures aredesirably chamfered to facilitate radially outwardly swinging movementof such tufts and to avoid sharp edges 3,382,521 Patented May 14, 1968"ice engaging the wires comprising the latter. An inner sheet metal cup7 is juxtaposed to the inner face of disc 4 and has a peripheral flangeportion 8 adapted to engage the radially inner sides of the bightportions of the twisted wire bristle knots or tufts 6. Cup 1, disc 4 andcup 7 are concentrically apertured at 9 for mounting upon a flexibleshaft or the like which is ordinarily provided with a retaining nut (notshown) internally of cup 7. Such cups and discs are integrally joinedtogether as by means of spot welds such as 10.

The outer sheet metal cup 1 is more shallow than has been the case inthe usual prior art cup brush and the lip 3 thereof will desirablyextend only very slightly further than the edge of disc 4 in a directionparallel to the axis of rotation of the brush, thereby enabling thetufts 6 to swing or pivot in their retaining apertures in a radiallyoutward direction under the influence of centrifugal force when thebrushing tool is rotated at high speed, the outwardly flaring lipportion serving to control the extent of such outward swinging movementand to support the tufts or knots when they have thus swung outwardlyinto positions very nearly those of tufts in a conventional wheel brush.Cups 1 and 7 thus provide a brush tuft bight receiving channeltherebetween which serves to regulate the positions which may be assumedby such tufts without however tightly clamping the bight portions of thetufts therebetween.

In the manufacture of the brush of this invention cups 1 and 7 willordinarily be preformed sheet metal stamp ings prior to assembly, butthe tufts of wire bristles may be inserted through the apertures 5 ofthe flat heavy gauge steel disc prior to deformation of the latter, theouter peripheral portion of such disc being then deformed as shown inFIG. 2. Alternatively, the tufts of wire brush bristle material may beinserted through apertures 5 and twisted into knots after the outerperipheral portion of disc 4 has been preformed. The depth of flange 8of inner cup member 7 is selected such that it extends in a directionaxially of the brush only slightly beyond the edge of deformed disc 4and preferably likewise only very slightly more in such direction thanlip 3 of outer cup member 1. Consequently, the bight portions of theknots or twisted tufts are embraced between the sides of such respectivecup members to control and regulate the positioning of such tuftswithout substantially clamping or compressing such bight portions in themanner of prior art cup brushes where such knots are tightly constrainedWithin a relatively deep retaining channel portion. Not only are thetufts thus permitted to pivot or swing outwardly as above described, butalso the brush bristles are permitted to flex throughout substantiallytheir entire length, thereby achieving the action of a relatively longtrim brush in use, in contrast to prior art cup brushes whereinsubstantial lengths of the brush tufts are held between the sides of achannelform back with bristle flexure accordingly limited largely to theportion of the bristle length protruding from such channel. Theapertures 5 through which the bristle tufts are inserted may desirablybe somewhat elongated, or oval, in radial directions. The ends of thebrush bristle tufts may be trimmed to proper uniformity before disc 4 isdeformed from the fiat to the FIG. 2 shape. In a typical brush, thetwisted tufts may be 2 /2" in overall length with 1%" extendingoutwardly beyond lip 3 of the outer cup 1.

It will be seen from the foregoing that a novel power driven rotarybrush of the twisted tuft type has been provided having numerousadvantages and benefits. When mounted on the usual power driven rotaryshaft, the nut securing the brush to the end of the shaft will normallybe within the confines of inner cup 7 where there is no danger ofcontacting and marring the work. Since the knots of twisted wire brushbristle material 6 are enabled to swing bodily toward a may accordinglybe operated in much the same manner and for many of the same purposes asanordinary wheel type brush, but is also very effective in acting uponinterior angles of workpiecesfor example. The inner cup 7 is so shallowthat it serves principally merely to support the bight portions of thebristle tufts, preventing radially inward pivoting of, such tufts beyonda position generally parallel to the axis of rotation of the toolwithout however tightly clarnping or constricting such tufts. The outeredge or lip 3 of the outer cup 1 is turned generally radially outwardlyto support the tufts when they have swung outwardly under the influenceof centrifugal force without however providing asharp edgecontactagainst such tufts which .mighttend to encourage long fracture of thebristles. As afpracticalmatter, it has been found that brushes inaccordance, with this invention are capable of withstanding more thantwice the amount of hard use,

measured in time, than the most closely similar cup brushes previouslyknown to applicants, and operators find themmuch easier to handle foroif-hand brushing operations and the likelt has been found that forcertain standard brush sizes the brush bristle tufts should betwistedtwo full turns as shown, a smaller degree of twist usuallyproviding appreciably inferior results. While twisted wire tufts orknots are usually preferred, other abradingelements such as tufts ofcrimped wire or even of straight wire held. in bundles may be employed,and the individual tufts or bundles may be impregnated with anelastomeric material such as foamed polyurethane; It may also be noted,as best shown in FIG. .2, that the outward slope or inclination offlange portion 8 of inner cup member 7 ispreferablysubstantially" lessthan the outward inclination of the corresponding side flange portion ofouter cup. member 1, it being desired thatoutward pivotal. movement ofthe tufts be facilitated whereas corresponding radially inwardlyswinging movement of the tufts should be relatively limited in use.

In the preferred embodiment of the iriventionillustrated, the cup brushthus comprises an outer sheet metal cup portion having .aperipheraloutwardly flaring flange,

a concentric inner sheet metal cup portion having a peripheral sideflangespaced from such first flange to provide .a circumferentialchannel therebetween, brush tuft retaining means interposed and securedbetweensuch inner and outer cup portions, and a plurality of brush tuftshaving innerend orbight portions secured to such retaining means. for atsubstantial amount of outward swinging movement when the brush isrotated at high Speed in use. The channel formed by the cup flanges ispreferably inclined to the axis of rotation of the brush,

and the outer side of such channelmay desirably be thus portion having aperipheral side flange spaced from said first flange to provide acircumferential channel therebetween, brush tuft retaining meansinterposed and secured between said inner and outer cup portions, and aplurality of brush tufts having inner end portions secured to saidretaining means, characterized in that said brush tuft re taining meanscomprises a sheet metal disc having a plurality of apertures about itsperiphery through which twistedwire bristle tufts are inserted andsecured for a substantial amount of outward swinging movement when saidbrush is rotated at high speed in use, the, bight por tions onlyof saidtufts being within the confines of said channel, and said side flange ofsaid inner cup portion flares outwardly to a lesser degree than saidoutwardly flaring flange of said outer cup portion.

2. The brush of claim 1, further characterized in that said outwardlyflaring flange of said outer cup portion said cups and discs areconcentrically apertured and joined together for rotation as a unit whenmounted on a drive shaft or the like.

4. The brush of claim 3, further characterized in that the length ofbristle tuft within the confines of such channel is much less than thelength of bristle tuft extending beyond such channel. I, I I

5. A power driven rotary brush comprising a circular back adapted to bemounted for rotation about a central axis normal to the plane of suchcircle, a circumferential channel portion of said back inclined to suchplane, the outer side of said channel flaring outwardly at a substantialangle to such axis, brush'material retaining means within said channel,and a single circular row of twisted tufts of brush material secured tosaidretaining means within said channel for substantial bodily outwardlyswinging movement to the extent permitted by said flaring outer side ofsaid channel, the lip of said outer side I of said channel being turnedgenerallyradially outwardly in a planesubstantially parallel to suchplane of such circle substantially directly opposite the region wheresaid brush material is thus swingingly secured to said retaining meansto permit said brush material to swing outwardly under the influence ofcentrifugal force intogenerally radially outward disposition.

6. The brushof claim 5, wherein the outer side of said channel extendsonly'slightly further than said retaining "means in the directionparallel to such brush axis.

7. A power driven rotary brush comprising a circular back adapted to bemounted for rotation about a central axis normal to the plane of suchcircle, a plurality of twisted tufts of brush bristle material pivotallymounted circumferentially of said back for bodily swinging movement frompositions generally parallel to the axis of rotation of said'brush topositions generally radially outward- I ly thereof, outercircumferential flange means effective to limit such outward swingingmovement, and inner circumferential flange means effective to limit suchinward- I ly swinging movement, said outer flange means terminatthefollowing claimsor theequivalent of such be em- We, therefore,particularly point out and distinctly claim as ourinvention: I

1. A power driven rotary cup brush comprising an outer sheet metal cupportion having a peripheral outwardly flaring flange, a concentric innersheet metal 7 cup ing in an outwardly projecting lip'in a planesubstantially parallel to such plane of such circle.

References Cited. UNITED STATES PATENTS 2,062,047 11/1936 Bickel'et al.e;.' 15-480

